IPAC2015 - List of Authors (Shobuda, Y.)

Paper	Title	Page
MOPWA058	Measurement Results of the Impedance of the RF-cavity at the RCS in J-PARC	255
	Y. Shobuda, H. Harada, H. Hotchi JAEA/J-PARC, Tokai-mura, Japan
	The kicker impedance dominates at the RCS in J-PARC. Recently, we observe beam instabilities, which are not explained by the kicker. As a candidate causing the beam instability, the impedance of the RF-cavity is measured. The longitudinal impedance is measured by stretching a single-wire inside the cavity. On the other hand, the measurement of the transverse impedance is done by horizontally shifting the single-wire, due to the accuracy problem. The measured impedance is too low to explain the beam instability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA058
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MOPTY001	Development of Wideband BPM for Precise Measurement of Internal Bunch Motion	937
	K.G. Nakamura Kyoto University, Kyoto, Japan Y.H. Chin, T. Koseki, T. Obina, M. Okada, M. Tobiyama, T. Toyama KEK, Ibaraki, Japan Y. Shobuda JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Funding: This work was supported by MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled “ Unification and　Development of the Neutrino Science Frontier” To suppress intra-bunch oscillations and to reduce particle losses, the intra-bunch feedback (IBFB) system has been developed in 2014 for the J-PARC Main Ring (MR). A new BPM was also installed to the MR for the IBFB system. This BPM has a sufficient frequency response and position sensitivity(up to 1.5GHz within 15% fluctuation ). However, a better performance may be needed in future for more precise analysis of internal motions (e.g. due to an electron cloud). We report the development of the BPM and precise measurement results of the BPM characteristics. We also report simulation studies of the digital equalizer which helps to reconstructs the beam shape from beam signals.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY001
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Measurement Results of the Impedance of the RF-cavity at the RCS in J-PARC

255

Y. Shobuda, H. Harada, H. Hotchi
JAEA/J-PARC, Tokai-mura, Japan

The kicker impedance dominates at the RCS in J-PARC. Recently, we observe beam instabilities, which are not explained by the kicker. As a candidate causing the beam instability, the impedance of the RF-cavity is measured. The longitudinal impedance is measured by stretching a single-wire inside the cavity. On the other hand, the measurement of the transverse impedance is done by horizontally shifting the single-wire, due to the accuracy problem. The measured impedance is too low to explain the beam instability.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA058

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTY001

Development of Wideband BPM for Precise Measurement of Internal Bunch Motion

937

K.G. Nakamura
Kyoto University, Kyoto, Japan
Y.H. Chin, T. Koseki, T. Obina, M. Okada, M. Tobiyama, T. Toyama
KEK, Ibaraki, Japan
Y. Shobuda
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Funding: This work was supported by MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled “ Unification and　Development of the Neutrino Science Frontier”
To suppress intra-bunch oscillations and to reduce particle losses, the intra-bunch feedback (IBFB) system has been developed in 2014 for the J-PARC Main Ring (MR). A new BPM was also installed to the MR for the IBFB system. This BPM has a sufficient frequency response and position sensitivity(up to 1.5GHz within 15% fluctuation ). However, a better performance may be needed in future for more precise analysis of internal motions (e.g. due to an electron cloud). We report the development of the BPM and precise measurement results of the BPM characteristics. We also report simulation studies of the digital equalizer which helps to reconstructs the beam shape from beam signals.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY001

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)